I can not possibly be the only person annoyed with this insanely stupid feature on my remote car starter, not to mention what I need to go through to get it to start. I was really liking driving Hyundai vehicles until I purchased the Elantra engine has even replaced, steering column replaced and I have not owned it for 2 years yet. So very disappointed in the whole experience

 

Whatever will work,
If type of horn permits, stuff a piece of rag into the horn or cover with a bag. Desired loudness of horn can can be regulated by thickness of covering.

We even have to do this when working on a vehicle where horn operation is involved.Cheap. easy and works.

 

This is a great idea except the horn would need to be buffered for all uses if this is done, I would love to have the horn disconnected from the remote starter

 

The horn has a relay that when activated sends power to the horn

I don't know of any way to diminish the horn volume when activated by the alarm system.

If,,,,,,,,,,,,, the regular wiring set up to operate the horn was opened/interrupted and a separate wiring set up installed to operate the horn just by the operator , that could be accomplished, but would require someone who would be very familiar with wiring to do this.
Is there any way you might find a happy medium?